Director circuits



DIRECTOR CIRCUITS Original Filed Feb. ll, 1924 2 Sheets-Sheet 1 lm. in.

m H 9 0 m Inuarzur- .E'harlss Ezllmgs 2 Sheets-Sheet 2 C. GILLINGS DIRECTOR CIRCUITS 0riginal Filed Feb. 11, 1924 July 3, 1928.

-Inusn u Iharlas 512121195 Patented July 3, 1928.

UNITED STATES PATENT OFFICE-1.

CHARLES GILLINGS, OF LIVERPOOL, ENGLAND, ASSIGNOR, BY MESNE ASSIGNMENTS,

T0 AUTOMATIC ELECTRIC INC, OFCHICAGQ. ILLINOIS, A CORPORATION OF DELL.-

WARE.

DIRECTOR CIRCUITS.

Application filed February 11, 1924, Serial No. 692131, and in Great Britain January 30, 1923,v Renewed November 23, I927.

The present invention concerns improvenicntrit in or relating to telephone. systems and more particularly relates to improvements in or a modification of the system claimed in the British Patent No. 194,427.

In that specification an arrangement is described by which impulses dialled by a calling subscriber in accordance with the exchange required which are represented by letters corresponding tothe first three letters in the name of the exchange required, are converted into another code consisting of series of impulses which control the operation of select-or switches to establish connection to a trunk line leading to the exchange required.

In the prior arrangements itwas proposed to provide register sets consisting of a 10 point switch, and a number usually eight 100 pointswitches, which were adapted to respond to the first three digits dialled by a calling subscriber to control impulse sending r \ices- The impulse sending device an the register switches were selected through the medium of a line switch individual to an outgoing trunk line taken into use when a subscriber lifted his receiver.

In the British Patent No. 194,580, it was proposed to employ a hundred point. switch individual to each outgoing primary trunk which responded to the first impulse and then hunted automatically tofind an idle register set of the class required. This arrangement had the advantage that the register translator sets were of a much simpler nature than was possible in the prior arrangement, and therefore tended on this ac count to an economy. This economy, was, however, somewhat reduced in that the register switches being individual to the outgoing primary trunks were a somewhat expensive item, and a desirable. modification was shown therefore according to which the register selectors were made common to the trunks by introducing secondary line switches.

According to one feature of. the present invention the arrangement described in the British Patent No. 194,580 is modified by substituting finder switches for the secondary line switches, the circuits being suitably revised to take care of the somewhat different operating requirements of the new arrangements. This decreases the total. numsibleto dissociate all.- the register translator equipment froma calliin case of failure to complete a connection due to faults or because the subscriber has failed to dial any or. all the digits.

A further feature of the invention relates to a method for reducing the holding time of'the registers in case-ofany of the groups ofswitclies which are required for a connec tion being all busy, the registers being released under the control of the busy signalling arrangements. p v

A novel feature by which the above results are attained consists of a holding circuit comprising two relays energized in series one associated with the outgoing trunk line, and the other associated with the register selector. By connecting battery or earthpotential direct to the junction point of the two relays, which is accessible to devices as sociatcd with. both the trunk line and the register selector, it is possible to cause either relay to deenergize. One relay can therefore be used to call the attention of an operator, while the other relay can control the release of the register devices. Another feature consists of the provision of air iinpulsin relay associated with the outgoing trunk line and adapted to be controlled by the register sender to control the setting of the first selector and over aloop circuit, the setting of all the other switches used in setting up a connect-ion.

In addition to the British patents referred to hereinbefore, this application may be considered; as an improvement on or a modi- .fication of the following prior, pending U. S.

applications: Nelson et al,.S. N. 538,551, filed Feb. 23, 1922, Richardson, et al, S. N. 547, 866,. filed March 29, 1922, Nelson, N. 573,175, filed July 6, 1922, Grillings, S. N. 598,239,, filed Novemberl, 1922..

In order that they inventionv may be clearly understood and readily carried into effect, a telephone systemv in accordance with them vention. will. now be more fully described with reference to the accompanying drawings in which Fig. 1 shows a jack and call lamp at a supervising operators position while Figs. 2 and 3 show the connections of the plugs which may be provided at the same position.

Fig. 1 shows a group of relays associated with an outgoing primary trunk and a first selector switch.

Fig. 5 shows a finder switch and a register selector while Fig. 6 shows a portion of the impulse registering, translating and sending apparatus selected by the register selector.

The general object and scope of the invention having been pointed out, the operation of the apparatus involved will now be de scribed more in detail, and for this purpose it will be assumed first that the calling subscriber has lifted his receiver and his associated line switch has selected the idle outgoing primary trunk a, b, 0, Fig. 4;. When the line switch seizes the outgoing primary trunk, the following circuit is completed for the line relay A: battery, upper winding of line relay A, back contact and armature 73, conductor a, over the calling subscribers loop, conductor 6, armature 7 and its back contact, lower winding of relay A to earth. Line relay A upon energizing, closes a circuit for slow release relay B at armature 3 and at armature 4 prepares one point in circuit of switching relay D. Slow release relay B upon energizing, earths the trunk release conductor 0 at armature 5 and at the back contact of armature 6, removes guarding potential from test conductor C and at front contact of said armature prepares one point in the circuit of stop relay C. At armature 7 relay B completes a circuit for supervisory lamp L, at armature 8 connects the holding conductor h to one side of the supervisory relay E and at armature 9 earths the common start wire SW. lVhen earth is connected to the start wire, the following circuit is completed for the start relay A of the finder switch FS, Fig. 5: earth, armature 9 and its front contact, back contact and armature 10, start wire SWV, armature 11 and its back contact, slow release start relay A to battery. Start relay A upon energizing completes the fol lowing circuit for the finder switch driving magnet M: earth, armature 12 and its front contact, winding of switching relay B, interrupter contacts 13, driving magnet M to battery. Relay A at armature 14 connects the junction point 15 between the driving magnet and the switching relay B over the back contact of armature 16 and conductor 17 to the finder switch test wiper TW and at armature 18 opens one point in the circuit of conductor 19, which leads to the next finder switch. When the start relay A energizes as above described, the driving magnet M commences to operate and rotates its wipers until the test wiper TlV engages bank contact 20 from which the guarding potential has been removed by the operation of slow release relay B. As soon as the calling trunk line is found, switching relay B energizes, having been previously short circuited by the normal earth potential on the test contacts in the bank of finder switch FS. Switching relay B completes the following locking circuit for itself in series with supervisory relay E, Fig. at: earth armature 21 of stop relay C, Fig. 4, make-before-break contacts controlled by armature 9.2, winding of supervisory relay E, front contact and armature 8, holding conductor 71,, bank contact 23, wiper 24, conductor 25, armature 26 and its front contact, winding of switching relay B, interrupter contacts 13, driving magnet M to battery. Supervisory relay E energizes in this circuit, and at armature 22 completes a locking circuit for itself, at armature 27 opens the circuit of supervisory lamp L, at armature 28 pre pares one point in the locking circuit of stop relay 0 and at armature 29 connects the dial tone to the calling party over the following circuit: dial. tone lead DT, off-normal springs 30, conductor 31, wiper DlV, bank contact 32, conductor 33, armature 29 and its front contact, back contact of armature 2 to outgoing primary trunk conductor 2').

Switching relay B at armature 11 opens the circuit of start relay A, which deenergizes shortly afterwards. hen earth connected to test wiper TW, by the operation of armature 16, a circuit is completed over test conductor C and armature 6 for stop relay C. Stop relay C upon energizing com pletes a locking circuit for itself at armature 34, opens at armature 21 the initial energizing circuit for supervisory relay E, and at armature 1O removes earth from the common start wire SlV. Switching relay B at armature 37. prepares the following iinpulsing circuit for vertical magnet V of the r: L 5191 selector switch RS, Fig. 5: battery, vei LlCfll magnet V, slow series relay C, back contact and armature 35, conductor 36, armature 3' and its front cont-act, impulse wiper 38, bank contact 39, conductor 10, armature 4 and its back contact to earthed release trunk conductor c.

When the calling subscriber hears the dial tone, he commences to dial and by internipt ing the loop a, 6, line relay A at armature 4 closes the circuit of the vertical magnet V a corresponding number of times, there-by raising the wipers 41 1.5 inclusive, opposite to the desired level. Relay C energizes and remains energized during the vertical movement of the switch, and on the first vertical step the off-normal springs 46 and the double dog springs 47 close a circuit for stepping relay E. Relay E at armature 4S establishes a locking circuit for itself and at armature l9 prepares a circuit for the rotary magnet E. An instant after the vertical movement of the switch is completed, slow relay C releases and completes the circuit of the rotary magnet E which advances the wipers 41-45 inclusive, into engagement with the first idle set of contacts in the level opposite to which they were raised. Assuming that the bank contacts 5()5 l inclusive,

extending to a B and C register switch of the class required are idle, then the rotation of the register selector RS will cease, and the switching relay D will operate. Relay D effects the following circuit changes: at armature connects earthed conductor 56 to test wiper 44: thus marking the test contact 53 and its multiples in the banks oi other register selectors busy: at armature 35 transfers the impulse circuit from the 'vertical magnet V over conductor 57 to wiper 43, at armature 58 connects wiper 4-2 over conductor 59, Wiper 60, bank contact (51, conductor 62, armature 63 and its hacl-r contact, back contact and armature 6% to the vertical mag net V of the first selector i and also to slow relay C in parallel with the "vertical magnet; at armature 65 connects wiper 4-1 over conductor 66, Wiper (i7, haul; contact 68,

conductor 69 to relay F and battery; at armature 70 connects wiper i5 over conductors 71, 72 and 25, wiper 24, bank contact 23 to the holding conductor h,

The output and input impulsing circuits having been connected up over wipers -i-l-2 and 43, respectively, by the operation of switching relay D the ren'iainingoperation of the first selector E is identical. with that already described in the British Patent No. 194,580 and in my prior U. application Serial No. 673,683. filed l loyemher i), 1.923, except that relay C is energized in parallel with the vertical magnet V. This has the advantage that it can be operated, alter the vertical magnet has oeen cut out of circuit, for each series of impulses sent over the output circuit. I

The registering, translating and sending apparatus is almost identical with that described in the speci cations ahove referred to and is therefore not dtserihed in det il, certain relays only being shown in Figure 6 which have reference letters ccr pending to similar relays in the above 111 cued British Patent No. 194 580 the circuit connections of which are slightly altered in the present invention.

After the calling party has dialled the wanted nuniher and the re ing and sending apparatus hi, the necessary impulses, a circuit c for switching relay l), l i earth over hank Contact 52, i conductor 57, frontcontact a a conductor 36, armature 37 and its front contact, wiper 38, hank contact 39, conductor 4:0, arn'iature t and its front contact, norn'ially closed contacts controlled by the upper armature of relay 1), switchin relay D to battery. Relay D upon energizing completes a holding circuit for itself at upper armature; at armaturcs 73 and T4. switches the calling party direct to the selector E and at the same time opens the circuit of line relay A at armatures 73 andTF-"l. inlay A upon deenergizing opens the circuit or? slow relay B at armature 3. Relay .13 upon decnergizing removes at armature 8 earth through relay E from holding conductor 70 thereby causing the release of switching relay l), which at armature T5 closes a circuit l'or release mag net RM oi the register selector RS; the circuit oi the release magnet being broken at oil-normal springs 76 when the switch shaft reaches normal position. The tinder switch FS, register selector RS and the registering translating apparatus are thus made ready for another call.

The purpose of the supervisory relay E, Fig. 4, will now be described. Assuming in the first case that when a calling party dials a particular digit all the registers of the class required are busy, then the register selector RS Will automatically rotate its wipers in known manner until the 11th contact position is reached, whereupon the cam springs 77 are operated. The closure of these springs connects the busy flash lead BF to the holding lead It, that is, positive and negative poles of battery alternatively. The connection of the positive pole, which is earth, short circuits relay E which thereupon de energizes and closes at armature 27 a circuit for lamp L at a supervising operators position, Fig. l. The connection or" the negative pole of battery to conductor 72 short circuits switching relay 13 of the finder switch FS which relay releases there by rendering the finder available for another call. The operator upon seeingthe lighted lamp L inserts the plug P, Fig. 3, into the jack J, the tip and ring springs of which areconnected to the a and Z) conductors of the primary trunk in question, and by means of her speaking set associated with the plug P asks the. calling party to call again.

The same ettect is produced it either first or other selectors taken into use should have all their outgoing lines in the required direc tion busy. In this case, however, the busy flash is connected to the h conductor by way of the positive trunk line conductor. As-

, suming that the busy flash earth is connected Illlh controlled by the switching relay D so as to be out of circuit when the registering translating and sending apparatus has sent out all the necessary impulses.

In order that the register selector RS and the register translator associated therewith should not be kept in use for an excessive length of time in the case of these busy flash connections, innnediately negative battery from the busy flash lead is connected to the positive trunk. or its equivalent in the case of overflows from the register selector RS, the finder switch holding relay is short circuited and releases the finder and all the register translating and sending apparatus.

In case the calling party should lift his receiver and neglect to diah the connection is also switched to the supervising operator. This is effected by means of the pick-up cam T which connects earth to the lead PL every thirty seconds. In this case rs will have operated but the switch RS will not be moved from its normal position. Consequently a. circuit will be completed as follows: earth on lead PL. oil normal contact 95. armatures 96 and 97, upper windingof relay F to battery. Relay F is marginal and only armature 98 moves to complete circuit from the lower winding of relay F to earth on armature 75 via armature 99. As soon as the pick up cam T removes earth from lead PL the two windings of relay F are energized in series and all the arm atures are attracted thus preparing a circuit for relay G over armature 120 and oil normal springs 95 to lead PL. After the lapse of thirty seconds relay G is energized over this circuit and at armature 121 connects earth to lead 72 thereby short circuiting relay E Figure to call in the supervisory operator. It is clear that if dialling should commence during this interval, the locking circuit of relay F would be opened at armature 99. Relay G is locked up via armatures 192 and 123 to the earthed conductor 56. If the calling party should dial one digit but less than a. complete number the relay which is energized by the pick up relay in the register translator, is provided with contact springs arranged to connect direct earth to bank contact it. thus earthing the holding lead 71 and short circuiting relay E with the here inbefore described results. In these cases the finder FS is not released automatically but only after the supervisory operator has inserted her plug P in the jack J and operated hey K which connects earth to the sleeve of jack J. The application of ground to the sleeve of the jack J results in the ODOIQlZlb tion of the switching relay D. whereupon line relay A. being cut off, deenergizes and places ground on lead 410. The application of ground to lead results in a circuit be ing closed through series relay C of the register selector RS for the vertical magnet V.

Relay C energizes in series with vertical magnet V and unlocks relay F at armature 99 v whereupon relay F deener rizes and unlocks relay G at armature 1." I permitting (:l to deenergize and unlock B at armature 3?. Relay B opens the circuit of the vertical magnet V at armature 37. The pick up rela and the relay energized thereby, if a delay occurs after the first digit and before the second or third digit may be the relays 20S and 205 shown in Fig. 2 of my (to-pendl nited States application Serial No. ()l-Liltii'i. filed November 9, 1923, but as the operation of these relays similar to the operation of relays F and G (Figure 6) and in itself forms no part of the invention disclosed they are not shown in the present application. The great advantage in this case is that the pick up arrangement comes into use at any time when there is an eX- o pause between digits and also it the e is a pause before impulses are sent and as this is provided individual to the finder switch it becomes much less expensive than if it was provided individual to the outgoing trunk. It may also happen that a suhscribefis line is either permanently earthed or that the lines are short-circuited and in this case it will be appreciated that the supervisory relay E will again come into action by means of the before mentioned pick up arrangement and the lamp L will be lit to attract the attention of the supervisory operator. The operator upon plugging into the jack J can either by simply pressing the key K operate the switching relay D and release all the register equipment. or if the fault due to a permanent earth or to any faults in the relays or first selector switch, connect a permanent earth to the sleeve of jack J by inserting the plug P. Fig. 2 which has its sleeve permanently earthed. This completes a circuit for switching relay D which at its upper armature or looking con tacts extends earth from the sleeve conductor of the jack to the release trunk conductor 0 thereby making the line non-selectable. If the registering translating and sending apparatus is provided with an alarm relay such. as relay 559, in Fig. 2. of my co-pend ing United States application Serial No. 673.683, filed November 9, 199.3. which relay is operated when the sending of digits is r. elayed by faulty operation of the impulse sending apparatus. this alarm relay may be provided with contacts adapted to connect earth direct to bank contact and the holding lead h. and thereby short-circuit supervisory relay E and call the operator in on the connection.

Referring now to Fig. 6. the relays 106, 107, 210 and lll corresponding to relays 106. 107. 210 and 111, respectively, shown in Fig. 3 of the British Patent No. .94.580 and since they perform the same function it is 1 Oil not thought necessary to again describe their operation in full. In the present case, however, relay 111 is controlled by relay- 210; this is to insure that relay E, Fig. 4, operates over the following circuit: earth, contact 101, resistance 1 11, contact 102, lead 103, contact 50,wiper 41, contact 65, lead 66, wiper 67 contact 68, lead 69, relay F to battery before earth is connected to the output wiper 12,. Fig; 5, in the following circuit: earth, contact 101, contact 104, conductor 105, contact 51, wiper 12. If this provision were not made Vertical magnet V of the first selector E might receive a preliminary impulse before relay F energized to open its circuit.

Relay 210 is the holding relay which is energized as soon as an idle register translator is taken into use and completes the two circuits mentioned above immediately on encrgization, one shortly before the other which is of course controlled by relay 111 and only indirectly by relay 210. Relay F operates in thetirst circuit and at armature 63 opens one point in the circuit of the vertical magnet V of the first selector E. Relay 111 upon energizing connects earth over the following circuit to armature 63 of relay F: earth, armature 101, armature 10 1, conductor 105, bank contact 51, wiper 42, armature 58 and its front contact, conductor 59, wiper 60, bank contact 61, conductor 62, to armature 63 of relay F. Impulses are generated in the usual manner by impulse relay 107 which at armature 102 interrupts the circuit oi? relay F: at each deenergization oi? relay F causes an impulse to be transmitted to the vertical magnet V at armature 63. The vertical magnet V ste s the wipers S0, 81 and 82 up opposite to the desired level whereupon the rotary magnet 83 rotates then in search 01: an idle line in that level and when an idle line is reached switching relay 84 operates and extends conductors 85 and 86 over armatures 87 and 88 to conductors 89 and 90 which terminate in the impulse relay of a second selector. The next series of impulses gene *ated by the impulse relay 107 causes the operation of the line relay ot the second selector over the following circuit:conductor 89, wiper 80, armature 87, conductor 85, contacts 91, resistance 92, armature 93, back contact and armature 9 1, conductor 86,.arn'1ature 88 and its front contact, wiper 82 to conductor 90. Relay F is controlled 89 and 90 at armature 93.

in the hereinbefore described manner and at each deenergization opens the loop circuit extending over conductors It will thus be seen that earthed impulses operate the first selector E and loop impulses the second and succeeding switches. The release is effected in known manner b the removal of earth from the release trun conductor when the calling party hangs up.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. In a telephone system, a trunk line, a plurality of call directors,-means for temporarily connecting one of said call directors with said trunk line to aid in setting up a connection thereover, an operatoris switchboard, a signal thereat, means for operating said signal automatically responsive to an abnormal condition arising during the process of setting up a connection over said trunk line, and multiple connections between said switchboard and said trunk line to enable an operator to converse with the calltransmission of each of said series of impulses to open the last named connection.

3. In a telephone system, a trunk line terminating 111 an automatic switch, an operating magnet for said switch, a repeating relay, a call director and means for connecting the same to said trunk line, a circuit for said magnet ncluding normally closed contacts on said repeating relay and normal lyopen contacts in said director, and means in said director for closing a circuit for said repeating relay and for closing said normally open contacts.

Signed by me at Liverpool, England, this 22nd day of January, 1924.

CHARLES GILLINGS. 

